MEMS (Micro Electro Mechanical Systems) is a miniature integrated system which manufactures a micro-structure, a micro-sensor, a micro-actuator, a control and processing circuit, even an interface, a communicator and a power supply on one or several chips, taking advantage of a manufacturing method for integrated circuit and a micromachining technology. Due to the development of MEMS technology, taking advantage of MEMS technology to manufacture sensors, for example, a pressure sensor is extensively applied in the consuming electronic field. Manufacturing MEMS pressure sensor requires manufacturing a support beam, a support beam structure of a conventional MEMS pressure sensor, which is connected to a mass block, is formed when a deep channel is formed in the back-etching process. The support beam has a height of about 350 μm. In the process of etching a channel, the uniformity and the homogeneity of a width of the support beam is difficult to be controlled, thus resulting in an inconsistency of shedding time of the mass block in subsequent KON etching process, causing the etching time the piezo-resistive diaphragm to be different, and the piezo-resistive diaphragm has an inconsistent thickness, thereby a consistence of the parameter of the pressure sensor device is poor. In order to control and guarantee a uniformity and homogeneity of the support beam structure, the etching process of the deep channel is required to be accurately controlled, thus reducing production efficiency and it is not conductive to reduce a production cost. In the conventional technology, a poor uniformity and a poor homogeneity of the support beam is presented.